深入理解 Go 语言有缓冲通道：何时以及如何使用？

package main

import (
    "fmt"
    "sync"
    "time"
)

// Task represents a simple task with an ID
type Task struct {
    ID int
}

// worker simulates a Goroutine that processes tasks
func worker(id int, tasks <-chan Task, results chan<- string, wg *sync.WaitGroup) {
    defer wg.Done() // Decrement the counter when the worker Goroutine exits
    for task := range tasks {
        fmt.Printf("Worker %d started processing task %d\n", id, task.ID)
        time.Sleep(1 * time.Second) // Simulate a time-consuming operation (e.g., 1 second)
        results <- fmt.Sprintf("Worker %d finished task %d", id, task.ID)
    }
    fmt.Printf("Worker %d shutting down.\n", id)
}

func main() {
    const numWorkers = 3      // Number of concurrent worker Goroutines
    const bufferSize = 5      // Capacity of the buffered channel for tasks
    const numTasks = 10       // Total number of tasks to be processed

    // Create a buffered channel for tasks
    tasks := make(chan Task, bufferSize)
    // Create a buffered channel for results (large enough to hold all results)
    results := make(chan string, numTasks)

    var wg sync.WaitGroup // Used to wait for all workers to complete

    // Start worker Goroutines
    for i := 1; i <= numWorkers; i++ {
        wg.Add(1) // Increment WaitGroup counter for each worker
        go worker(i, tasks, results, &wg)
    }

    // Producer: send tasks to the buffered channel
    // This loop will not block until the buffer is full (i.e., 5 tasks are sent and not yet consumed)
    fmt.Println("--- Scheduler starts sending tasks ---")
    for i := 1; i <= numTasks; i++ {
        task := Task{ID: i}
        tasks <- task // Send task to the channel
        fmt.Printf("Scheduler sent task %d to channel\n", task.ID)
        time.Sleep(100 * time.Millisecond) // Simulate scheduler doing other work (e.g., 0.1 second)
    }
    close(tasks) // Close the tasks channel when all tasks are sent, signaling workers no more tasks are coming

    // Wait for all workers to finish processing tasks
    wg.Wait()
    close(results) // Close the results channel after all workers are done and have sent their results

    // Collect and print results from workers
    fmt.Println("\n--- Collecting Results ---")
    for res := range results {
        fmt.Println(res)
    }
    fmt.Println("All results collected. Program finished.")
}